COMPLEX REGIONAL PAIN SYNDROME

1. COMPLEX REGIONAL PAIN SYNDROME Arthur R. Smith, MD January 13, 2009

2. COMPLEX REGIONAL PAIN SYNDROME • History • Epidemiology • Definition & Taxonomy • Causes • Clinical Presentation • Diagnostic Tests • Pathophysiology • Treatments

3. 1864 - Colonel Weir Mitchell, MD“severely painful dystrophic syndrome following ballistic injuries” in Civil War soldiers: Causalgia

4. History • Paul Sudeck • Suggested that the signs and symptoms of RSD may be caused by an exaggerated inflammatory response to injury or operation of an extremity. • Sudeck’s Atrophy: Bone loss associated with RSD

5. Rene Leriche Sympathetic nervous system dysfunction as a cause of pain. Therapeutic surgical sympathectomy

6. John Bonica • The syndrome much as we know it today • Promoted the term RSD • Described 3 stages

7. Epidemiology • CRPS I: 21 per 100,000 • CRPS II: 4 per 100,000 • Female-to-Male ratio: 3:1 • Any age, but middle age predominates • Median 42 years • Onset 9 – 85 years of age • CRPS occurs in about 1-2% of patients who have had fractures and in approximately 2-5% of patients after peripheral nerve injuries

8. Complex Regional Pain Syndrome: a variety of painful conditions following injury which appears regionally having a distal predominance of abnormal findings, exceeding in both magnitude and duration the expected clinical course of the inciting event, often resulting in significant impairment of motor function, and showing variable progression over time.

9. IASP Nomenclature • CRPS I = Reflex Sympathetic Dystrophy • CRPS II = Causalgia • The only difference between the two is the inciting event: minor trauma (I) versus major peripheral nerve injury (II). • Algodystrophy, Sudeck’s atrophy, sympathetically maintained pain, shoulder/hand syndrome, transient osteoporosis, and acute atrophy of bone.

10. Clinical Presentation • Precipitating event: • CRPS I • Minor trauma, contusion, sprain or strain • Fracture (especially colles fx) • Post surgical • Immobilization • Less frequently: CVA, spinal cord injury • CRPS II • Documented peripheral nerve injury and concordant focal deficits (but the signs and symptoms of CRPS are not limited to the same distribution as the affected nerve.)

11. Clinical Presentation • Usually an extremity(65%) , but any part of the body can be affected. • CRPS may progress and spread to other extremities over time.

12. Clinical Presentation • PAIN, PAIN, PAIN • Spontaneous, constant, burning, aching, throbbing • Disproportionate to the injury and persists beyond normal or expected recovery period • Asymmetrical and not in the distribution of a peripheral nerve. Worst distally. • Severe mechanical and thermal allodynia, hyperalgesia, and hyperpathia

13. Clinical Presentation • Autonomic (Sympathetic) Abnormalities • Vascular • Hot, swollen, erythemetous • Cold, blanched • Mottled • Sudomotor • Hyperhydrosis • Hypohydorosis

14. Clinical Presentation • Motor • Diffuse weakness of the extremity, but normal EMG/NCS until late in the course of the disease. • Tremor • Dystonia occasionally

15. Clinical Presentation • Trophic Changes • Nail growth • Loss of function: muscle, joint and tendon atrophy, contractures and fibrosis • Hair changes (coarse hair, loss of hair) • Skin--thin and glossy, loss of elasticity, ulceration. • Osteoporosis

16. Clinical PresentationTime Course • Three stages: • Stage 1 (acute) • Stage 2 (dystrophic) • Stage 3 (atrophic)

17. CRPS Stage 1 (Acute)Immediately after injury--3 monthsMOST LIKELY TO BE REVERSED AND CURED • SKIN: Red, warm, swollen, dry, inflamed. Later color may change to mottled and colder with marked hyperhydrosis. Changes back and forth especially with painful use. • DISTRIBUTION: Pain is not compatible with a single peripheral nerve, trunk, or root lesion. • SYMPATHETIC: • VASOMOTOR: Disturbances occur with variable intensity, producing altered color and temperature. Hyperemic Mottled • SUDOMOTOR: Dry Hyperhydrosis • MOTOR: Decreased ROM, weakness • X-RAYS: Normal • BONE SCAN: Increased uptake

18. Stage 1 (Acute)

19. Stage 1 (Acute)

20. CRPS Stage 2 (Dystrophic) • Pain remains SEVERE. Same characteristics as Stage 1.

21. CRPS Stage 2 (Dystrophic)6 weeks--1 year • SKIN: Cool, moist, tight/shiny, swelling, coarse/sparse hair, brittle nails, discolored, edema • SYMPATHETIC: • VASOMOTOR: Mottled/cyanotic • SUDOMOTOR: Hyperhydrosis • MOTOR: Weakness, decreased ROM • BONE SCAN: No longer helpful.

22. Stage 2 (Dystrophic)

23. Stage 2 (Dystrophic)

24. Stage 2 (Dystrophic)

25. CRPS Stage 3 (atrophic)6 months--Forever? • Pain is somewhat decreased (but still debilitating) • less at rest, worse with passive motion • Changes are irreversible, poor outcomes, permanent disability • SKIN: Atrophy, “waxy”, very thin, ulcerations, brittle nails • SYMPATHETIC: • VASOMOTOR: Cold, intermittently cyanotic/mottled • MOTOR: Decreased ROM, weakness, muscle & tendon atrophy, contractures, dystonia, tremor. Nonfunctional limb. • X-RAYS: Diffuse patchy osteoporosis (Sudeck’s Atrophy)

26. Atrophic Stage 3 Severe Mottling

27. Atrophic Stage 3 Contractures Skin Ulceration Migratory/progressive

28. Atrophic Stage 3 Contractures

29. Diagnostic TestsSympathetic Blockade • Sympathetically Maintained Pain • Previously synonymous with CRPS • Sympathetic block was deemed diagnostic for CRPS. • Now considered a symptom of underlying neuropathic pain sydromes, including, but not exclusively, CRPS.

30. SYMPATHETICALLY MAINTAINED PAIN PHN PHANTOM LIMB SMP CRPS PNP

31. Diagnostic Tests:Sympathetic Blockade • Stellate Ganglion Block • Lumbar Sympathetic Block A successful block (increase in temperature, for example) that results in pain relief helps confirm a diagnosis of CRPS in the presence of other consistent clinical findings.

32. Diagnostic Tests • Three Phase Bone Scintigraphy • Only in acute stage • Hyperperfusion • Suggestive and supportive of the diagnosis of CRPS, but not diagnostic

33. Diagnostic Tests • Plain Radiographs • Late findings only with atrophic stage showing bone loss and patchy osteoporosis

34. Diagnostic Tests Skin Temperature Thermography may show asymmetry. Affected limb is warmer than normal in acute stage and later becomes cooler. Not a readily available procedure.

35. Diagnostic Tests • Quantitative Sensory Testing: Rarely available and no specific profile for CRPS • QSART: Quantitative Sudomotor Axon Reflex Test of autonomic function. Rarely available

36. Diagnostic Criteria • Diagnosis is based on clinical findings although tests may support either a positive or negative diagnosis.

37. CRPS I Diagnostic Criteria - IASP • 1. The presence of an initiating noxious event or a cause of immobilization. • 2. Continuing pain, allodynia or hyperalgesia with which the pain is disproportionate to the inciting event. • 3. Evidence at some time of edema, changes in skin blood flow or abnormal sudomotor activity in the painful region. • 4. The diagnosis is excluded by the existence of conditions that would otherwise account for the degree of pain and dysfunction. • note: Criteria 2,3 and 4 are necessary for a diagnosis of complex regional pain syndrome. • International Association for the Study of Pain: Diagnostic Criteria for Complex Regional Pain Syndrome with 1997 ICD Codes • Merskey H,Bodguk N, eds. Classification of chronic pain, descriptions of chronic pain syndromes and definitions of pain terms. Id ed. Seattle: IASP Press, 1994:40-3.

38. CRPS II (Causalgia) - IASP 1. The presence of continuing pain, allodynia or hyperalgesia after a nerve injury, not necessarily limited to the distribution of the injured nerve. 2. Evidence at some time of edema, changes in skin blood flow or abnormal sudomotor activity in the region of the pain. 3. The diagnosis is excluded by the existence of conditions that would otherwise account for the degree of pain and dysfunction. note: All three criteria must be satisfied. International Association for the Study of Pain: Diagnostic Criteria for Complex Regional Pain Syndrome with 1997 ICD Codes Merskey H,Bodguk N, eds. Classification of chronic pain, descriptions of chronic pain syndromes and definitions of pain terms. Id ed. Seattle: IASP Press, 1994:40-3.

39. Pathophysiology • NOT KNOWN! • What we do know: • Neurogenic Inflammation (acute stage)

40. Pathophysiology

41. Pathophysiology

42. Pathophysiology

43. Pathophysiology

44. Treatment Goals • Relief of pain • Return of function • Prevent or slow progression EARLY TREATMENT IMPROVED OUTCOME =

46. Physical Therapy • In the acute stage PT is the most important factor in reversing the syndrome. • Later, it can improve pain & function and help prevent progression and migration. • Aggressive PT may only be possible with treatment of pain: pain meds, sympathetic and/or somatic blockade.

47. Medications • NSAIDs-Mild to moderate pain • Opioids-Effective for severe neuropathic pain. Beware of all issues related to chronic opioid use. • Steroids-Proven effective in acute (inflammatory) stage. • Gabapentin and Pregabalin-Effective

48. Medications • Tricyclics-Effective for a variety of neuropathies • Sodium channel blockers-IV lidocaine, Lidoderm, mexilitene, lamotrigine. • Calcitonin (intranasal)-Effective in acute stage. How? • NMDA blockers-Ketamine, dextromethorphan • DMSO (topical)- Free radical scavenger. Questionable benefit • Topical Clonidine- 2-agonist: prevents release of catecholamines? Maybe helpful.

49. Sympathetic Blockade • Lumbar sympathetic block • Stellate ganglion block • IV regional with guanethidine If effective, sympathetic blockade often gives relief well past the duration of the block. Repeated blocks can be reverse the course of the disease. Very helpful in facilitating PT.

50. Psychology (Psychiatry) • Earlier anxiety progresses to severe depression. (Pain, loss of work and self worth, financial loss, family breakdown, pain behavior, medication dependence and abuse) • Medical treatment of depression • Counseling, set realistic goals and expectations, behavioral & cognitive therapies, biofeedback, hypnosis.